The present invention relates to an assembly for controlling the filling of a vehicle fuel tank having a filler neck, and particularly to a filler neck without a removable outer fuel cap. More particularly, the present invention relates to a capless filler neck having an internal opening and closing mechanism and a liquid fuel and fuel vapor handling system which controls the discharge of fuel vapors from the tank and the filler neck both during and after the filling operation.
A removable fuel cap with a sealing gasket typically is used to close the open end of a fuel tank filler neck. Once the fuel cap is removed from the filler neck, the fuel tank is filled, and the fuel-dispensing nozzle is withdrawn from the filler neck, the fuel cap is reattached to the filler neck so that the sealing gasket forms a seal between the fuel cap and the filler neck. Thus, the fuel cap closes the open end of the filler neck to block discharge of liquid fuel and fuel vapor from the fuel tank through the filler neck. It is known, however, to place pressure-relief and vacuum-relief valves in fuel caps to permit some controlled venting of fuel vapors in the filler neck while the fuel cap is mounted on the filler neck.
It has been observed that fuel caps are often lost or damaged over time and, as a result, the open end of the filler neck might not be closed and sealed in accordance with the original equipment specifications during operation of the vehicle. Accordingly, a filler neck configured to "open" automatically as a fuel-dispensing pump nozzle is inserted into the filler neck during refueling and "close" automatically once the attendant withdraws the pump nozzle from the filler neck without requiring the attendant to reattach a fuel cap to the filler neck would be an improvement over many conventional capped filler neck systems. Although conventional fuel caps function to close filler necks in a satisfactory manner, it is thought that a capless filler neck could make vehicle refueling more convenient for the consumer because no action other than inserting a pump nozzle into the open end of the filler neck would be required to begin refueling a vehicle. Advantageously, such a capless filler neck system would be configured in accordance with the present invention to include internal liquid fuel and fuel vapor control means.
Filler necks with self-closing mechanisms are known. A capless vehicle refueling system including a closure member that is movable by a fuel-dispensing nozzle to open a filler neck is disclosed in U.S. Pat. No. 5,056,570 to Harris and Griffin. A quick-release fuel coupling for racing cars is disclosed in U.S. Pat. No. 3,938,564 to Jones.
A capless filler neck that is configured to control air and liquid flow into and out of the filler neck yet is assembled quickly and easily using only a few parts would be an improvement over known filler necks. There is a demand in the industry for an inexpensive yet effective capless filler neck that is reliable and easy to manufacture. An improved filler neck that does not require the use of a conventional fuel cap and that is configured to open automatically both during refueling to permit fuel dispensed by a fuel nozzle to flow into a fuel tank through the filler neck and after refueling to relieve unwanted excess pressure and vacuum conditions in the tank would be welcomed by many vehicle manufacturers.
According to the present invention, a filler neck is provided with an internal tube that is movable to open and close the filler neck. The movable tube is formed to include a fill passageway that extends therethrough and is configured to deliver fuel from a fuel-dispensing nozzle to a vehicle fuel tank when the filler neck is open. The "moving" fill passageway is closed when the filler neck is closed and opened when the filler neck is opened. An inlet opening into the moving fill passageway is formed in an outer end of the movable tube and an outlet opening for discharging liquid fuel from the moving fill passageway for delivery to the fuel tank is formed in an inner end of the movable tube.
The filler neck includes a conduit providing a vent passageway extending therethrough. The conduit includes an outer end formed to include a mouth and an inner end connected to the fuel tank. The vent passageway extends through the conduit between the inner and outer ends. A fill passageway closure member is appended to the conduit and positioned to lie in the vent passageway in spaced-apart relation to the mouth of the conduit.
The movable tube is positioned in the conduit for movement in the vent passageway to cause the fill passageway to engage or disengage the fill passageway closure member so as to control opening and closing of the filler neck during and after refueling. Thus, the tube is movable in the vent passageway to either a filler neck-closing position wherein the fill passageway is blocked by the closure member or a filler neck-opening position wherein the fill passageway is not blocked by the closure member.
The filler neck also includes spring means for yieldably urging the movable tube in the vent passageway toward the mouth of the conduit and into engagement with the closure member that is fixed in spaced-apart relation from the mouth of the conduit. This engagement causes the fixed closure member to close the outlet opening in the movable tube so that flow of liquid fuel and fuel vapor through the fill passageway formed in the movable tube is blocked. At the same time, the spring means yieldably urges the movable tube into engagement with a valve seat portion of the conduit that is closer to the mouth of the conduit to block flow of liquid fuel and fuel vapor through the vent passageway. Thus, the spring means functions simultaneously to bias the movable tube against both the closure member and the valve seat portion of the conduit to establish a filler neck-closing position of the movable tube inside the conduit.
Preferably, in use, a fuel-dispensing nozzle is inserted by a user through the filler neck conduit and into the fill passageway provided in the movable tube. By manually pushing the nozzle further into the conduit and against the spring-loaded movable tube, the tube can be moved against the spring means so that the tube disengages the fixed closure member to open the fill passageway and also disengages the valve seat portion of the conduit to open the larger vent passageway containing the movable tube. Opening the fill passageway in the movable tube allows liquid fuel to be discharged from the nozzle into the fuel tank through the movable tube. Opening the vent passageway in the conduit allows displaced fuel vapor in the fuel tank to escape to the atmosphere through the filler neck.
In preferred embodiments, the conduit includes a partition formed to include a central aperture. The partition is arranged in the conduit to divide the vent passageway into an outer chamber accessible through the mouth of the conduit and an inner chamber connected to the outer chamber through the aperture. The inner chamber is also connected to the fuel tank through a pipe. Preferably, the valve seat portion mentioned above is provided by a portion of the partition surrounding the central aperture and lying in the inner chamber.
A pair of pressure-relief valves are mounted in the partition next to the central aperture to control venting of excessive fuel vapor pressure from the inner chamber to the outer chamber and atmosphere while the movable tube is in its filler neck-closing position. A vacuum-relief valve is also mounted in the partition next to the central aperture to admit ambient air from the atmosphere outer chamber into the inner chamber and then the fuel tank as soon as vacuum conditions develop in the inner chamber or the fuel tank. Also, a drain passageway is provided in the partition next to the central aperture to drain any liquid such as rain water or the like that happens to collect in the outer chamber to a drainage outlet formed in the conduit so that such unwanted liquid is drained from the filler neck and unable to contaminate the fuel tank.
The fill passageway closure member mounted in the conduit is a tubular member that includes a distal end shaped to provide a plug for closing the fuel-discharging outlet opening of the fill passageway in the movable tube. The closure member also includes a base that is attached to a support frame mounted in the inner chamber of the vent passageway. The support frame includes a fuel transfer conduit extending through the inner chamber for conducting liquid fuel from the fill passageway in the movable tube into the pipe coupled to the fuel tank whenever the movable tube is in its filler neck passageway-opening position and liquid fuel is being dispensed into the fill passageway by a nozzle during refueling.
The spring means includes a coiled spring that surrounds the movable tube and extends along the length of the movable tube. The spring has one end that engages the support frame and another end that engages an exterior flange appended to the movable tube. A sealing ring is mounted to lie around the movable tube and abut the exterior flange. Normally, the coiled spring will urge the movable tube toward the mouth of the conduit and through the central aperture in the partition so that the sealing ring around the movable tube will engage the valve seat portion of the partition around the central aperture to establish a liquid fuel and fuel vapor seal between the partition and the movable tube.
The movable tube includes an internal flange in the fill passageway that is arranged to be engaged by the tip of a fuel-dispensing nozzle inserted into the inlet opening of the movable tube during refueling. A user can insert the nozzle into the outer chamber of the conduit and on into the fill passageway so that it engages the internal flange and then move the nozzle further into the conduit to urge the movable tube against the spring. This causes the movable tube to move to disengage the fill passageway closure member and thus open the fill passageway and to disengage the sealing ring and the partition so that the vent passageway is opened. Liquid fuel discharged from the nozzle is then able to flow through the fill passageway in the movable tube into the fuel tank. At the same time any pressurized fuel vapor present in the fuel tank and filler neck can escape to the atmosphere through the vent passageway formed in the conduit and the central aperture formed in the partition.
The improved capless filler neck of the present invention is easy to manufacture and assemble. A user can easily move the spring-loaded movable tube manually in the conduit from a filler neck-closing position to a filler neck-opening position by merely inserting a conventional fuel-dispensing nozzle fully into the filler neck. Once the nozzle is removed, the spring automatically returns the movable tube to its filler neck-closing position. Advantageously, the filler neck is provided with a partition having a pressure-relief valve, a vacuum-relief valve, and a drainage means to control inflow of air and liquid into the capless filler neck and outflow of pressurized fuel vapor out of the capless filler neck during and after refueling.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.